It is well known by designers of automobiles that the formation of water condensation on outside rearview mirrors and side windows is an undesirable phenomenon that causes inconvenience to drivers who must clear these surfaces to insure good visibility. It is also known that providing a ventilation path through the front edge of the vehicle's front doors as is conventionally accomplished with so-called vent windows is desirable in certain vehicles, particularly when air conditioning is not used.
The response of the automotive industry to provide components which will automatically remove condensation from one or the other of the mentioned glass surfaces or will provide a door ventilation path is well known. For example, U.S. Pat. Nos. 3,522,584 to Talbot; 3,859,899 to Mills; and 3,877,780 to Taylor disclose outside rearview mirrors which accomplish clearing of the mirror by passing heated passenger compartment air through it. That passing heated air over inside glass surfaces on which condensation may form is known is exemplified by U.S. Pat. No. 2,150,110 to Strauss et al. Lacking in the prior art, however, is teaching of the economical combination of any of these desirable functions in a single component assembly.